NSR250 SP MC18 R6k General Info

1989 NSR250R MC18 R5K & R6K. The face-lift MC18's went on sale in Japan in February 1989 and were immediately available in 3 colour schemes, the obligatory red & white and blue & white, but also a new black, red and silver-grey based on the colours of the successful SEED Racing team. These R5K models are easily identifiable by their high swept silencers, the stainless steel rear pipe from the expansion chambers to the silencers, and the sleeker windshield. They also had 4 large holes in the belly pan instead of the multi slotted panel like the earlier bikes.

The differences were more than cosmetic however... under the seat unit, away from prying eyes, the first of the "new generation" 3D PGM's was installed. This ignition unit was identical in appearance to the RS250's PGM-II but with a tamer ignition map for increased reliability and road orientated performance.

The R5K's were the first model to be fitted with a new 150 section Bridgestone rear tyre too, but still had no multi-way adjustable suspension, although a rear shock, c/w ride height adjuster, was available as an HRC TT-F3 option. No R5K SP's were released so there were still no dry clutch models, but the whole range benefited from an updated closer ratio gearbox. First gear remained the same, but the following 5 gears were closer. The R5K and R6K rear sprocket size was also increased from 41T to 42T, giving the stock bike more punch when accelerating, but the resulting final drive and closer ratios lowered the effective top speed a little, but as these bikes were speed limited anyway, it wasn't of prime concern.

The R6K models were the first true SP's. They sported the similar gold Magtek magnesium wheels as before, but now with the benchmark 150/60 series tyre, first seen on the R5K. This new SP also had adjustable suspension front and rear; spring preload and rebound dampening on the front, and spring preload, rebound, and compression dampening on the rear, and an all new dry clutch based on the RS250 race bikes.

Released to compete with Yamaha's new TZR250 Reverse Cylinder, Suzuki's first RGV250, and Kawasaki's KR1, it was (and still is) an extremely competent road and race bike capable of in excess of 70hp in full race trim! All R6K SP's were only produced in white and silver Terra Racing colours.

I raced an NSR250 in New Zealand in 1990 and can remember the 250cc production class required green number boards with white numbers. I assume this racing standard was an FIM standard that applied worldwide, and hence you see it on the pictures of the bike here.

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